To enhance the flexibility of a computer system, it is desirable to design a computer system such that additional peripherals can easily be added. However, portable computer systems are often difficult to expand since their small size precludes the use of many common expansion buses. Therefore, it is desirable to create expandable external ports on portable computer systems.
Most computer systems include a display unit for displaying information to a user. In prior art portable computer systems, the display unit is usually an integrated part of the computer system. However, to provide additional flexibility, it would be desirable to provide an external port capable of driving several different types of displays.